Fate

Hey bird... Did ya build the exact same circuit???

PIC?? ???

Hey Guru... Didn't quite get your point abt the output not going to zero... ??? BTW could u explain the PIC part of the circuit.. I'm totally new to the subject...

Hey Bird... Check out the data sheets for LM 358... Btw can't I like use two 741's instead? The specs are pretty much the same... LM358.pdf

Hey Trigger... The optical technique presented here exploits the fact that tiny subcutaneous blood vessels (capillaries) in any patch of skin (fingertip, ear lobe, etc.) furnished with a good blood supply, alternately expand and contract in time with the heartbeat. An ordinary infrared LED/phototransistor pair can sense this rhythmic change as small but detectable variations in skin contrast. That's pretty much the gist of the theory it's based on...

Are you working on the same thing? DesignGuide.zip

Muah!!! :D

:-[Hmmm... Now I want to amplify it (a lot)... feed the output to a comparator and then to a mono to get like proper pulses and then count them (per min)... Any more suggestions... ???

Hey... Thanx for the help but I already got my hands on that one... :P But I've to work without microcontrollers and Pic... :-\ Don't know...

Hey... I'm working on a heartbeat detector & monitor (using photodiode & detector not microcontroller) for my mini project and need help in designin it... Any kind of help will be greatly appreciated... Thanx